Theft and vandalism of automobiles is a significant problem in the United States. Heretofore, numerous devices have been developed to prevent unauthorized use of motor vehicles. One such device is described in U.S. Pat. No. 3,930,226 by Leonard G. Plumberg. That system is activated when one of the switches in the dome light circuit (e.g., door switches) is closed which causes the system to be grounded. Other systems known in the art function by detecting a voltage drop due to, for example, the dome light being switched on upon the door opening.
In these systems, false alarms are often created by the switching on of certain accessories such as fans, clocks, and onboard trip computers, even after the vehicle has been completely turned off. Thus, the current systems have become more complex due to the necessity of connecting the alarm's central unit directly to the particular accessories from which one wants to locate an electrical disturbance. Installing the corresponding wires inside each vehicle compartment, and between these compartments and the alarm's central unit, requires numerous drillings of the separation walls, and turns out to be lengthy, difficult and costly.
Accordingly, it is the principal object of this invention to reduce the complexity of automobile burglary detecting systems. Another object is to simplify the installation of burglary systems.